Tool use in chimpanzees (Pan troglodytes) is widespread across their geographical distribution, having been documented in all populations studied to date. Ant-fishing, specifically, is less frequently observed, reported so far in only ten different communities. We describe the first observations of ant-fishing of Camponotus chrysurus by chimpanzees living in the mosaic landscape of the Issa Valley, western Tanzania. After two separate bouts, both occurring in the same position in a fig tree (Ficus lutea vahl), we recovered five ant-fishing tools made from the liana Dichapetalum crassifolium chodat. Tool types closely resemble those described for earlier reports of the same behavior in near-by Mahale Mountains chimpanzees, and thus may have implications for cultural diffusion of the habit across populations
